Always build net45 on Linux
Always build net45 on Linux

The conditional build of net45 was added when we didn't support any
desktop targetframeworks on Linux. Now that it's supported we should be
building all flavors of the utilities there.

panopticoncentral/roslyn,heejaechang/roslyn,nguerrera/roslyn,mattscheffer/roslyn,KirillOsenkov/roslyn,gafter/roslyn,panopticoncentral/roslyn,AmadeusW/roslyn,agocke/roslyn,paulvanbrenk/roslyn,reaction1989/roslyn,lorcanmooney/roslyn,dotnet/roslyn,paulvanbrenk/roslyn,mattscheffer/roslyn,cston/roslyn,mgoertz-msft/roslyn,gafter/roslyn,eriawan/roslyn,genlu/roslyn,reaction1989/roslyn,bartdesmet/roslyn,gafter/roslyn,xasx/roslyn,jmarolf/roslyn,tmeschter/roslyn,nguerrera/roslyn,jcouv/roslyn,dotnet/roslyn,MichalStrehovsky/roslyn,agocke/roslyn,MichalStrehovsky/roslyn,tmeschter/roslyn,KevinRansom/roslyn,Giftednewt/roslyn,KevinRansom/roslyn,DustinCampbell/roslyn,tannergooding/roslyn,aelij/roslyn,Giftednewt/roslyn,tmat/roslyn,heejaechang/roslyn,wvdd007/roslyn,abock/roslyn,mavasani/roslyn,davkean/roslyn,ErikSchierboom/roslyn,jasonmalinowski/roslyn,DustinCampbell/roslyn,brettfo/roslyn,MichalStrehovsky/roslyn,bkoelman/roslyn,lorcanmooney/roslyn,jcouv/roslyn,davkean/roslyn,mavasani/roslyn,brettfo/roslyn,paulvanbrenk/roslyn,OmarTawfik/roslyn,shyamnamboodiripad/roslyn,physhi/roslyn,mattscheffer/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,DustinCampbell/roslyn,davkean/roslyn,tmeschter/roslyn,nguerrera/roslyn,diryboy/roslyn,eriawan/roslyn,diryboy/roslyn,KirillOsenkov/roslyn,eriawan/roslyn,CyrusNajmabadi/roslyn,ErikSchierboom/roslyn,tmat/roslyn,physhi/roslyn,tmat/roslyn,cston/roslyn,AlekseyTs/roslyn,AmadeusW/roslyn,jamesqo/roslyn,panopticoncentral/roslyn,sharwell/roslyn,CyrusNajmabadi/roslyn,VSadov/roslyn,weltkante/roslyn,diryboy/roslyn,dpoeschl/roslyn,reaction1989/roslyn,abock/roslyn,physhi/roslyn,jamesqo/roslyn,dpoeschl/roslyn,mgoertz-msft/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,ErikSchierboom/roslyn,heejaechang/roslyn,tannergooding/roslyn,AlekseyTs/roslyn,wvdd007/roslyn,dpoeschl/roslyn,stephentoub/roslyn,sharwell/roslyn,weltkante/roslyn,shyamnamboodiripad/roslyn,OmarTawfik/roslyn,KevinRansom/roslyn,mavasani/roslyn,brettfo/roslyn,AlekseyTs/roslyn,orthoxerox/roslyn,lorcanmooney/roslyn,Hosch250/roslyn,cston/roslyn,CyrusNajmabadi/roslyn,genlu/roslyn,shyamnamboodiripad/roslyn,jamesqo/roslyn,VSadov/roslyn,KirillOsenkov/roslyn,abock/roslyn,genlu/roslyn,weltkante/roslyn,bkoelman/roslyn,jasonmalinowski/roslyn,stephentoub/roslyn,jcouv/roslyn,stephentoub/roslyn,AmadeusW/roslyn,jasonmalinowski/roslyn,mgoertz-msft/roslyn,Giftednewt/roslyn,orthoxerox/roslyn,tannergooding/roslyn,aelij/roslyn,jmarolf/roslyn,bartdesmet/roslyn,sharwell/roslyn,swaroop-sridhar/roslyn,Hosch250/roslyn,xasx/roslyn,swaroop-sridhar/roslyn,OmarTawfik/roslyn,bkoelman/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,agocke/roslyn,orthoxerox/roslyn,Hosch250/roslyn,aelij/roslyn,jmarolf/roslyn,swaroop-sridhar/roslyn,bartdesmet/roslyn,VSadov/roslyn,wvdd007/roslyn,xasx/roslyn,dotnet/roslyn